Adjustable anti-siphon pin valve for paintball gun

ABSTRACT

An anti-siphon pin valve for a paintball gun is adapted to remove gaseous carbon dioxide from a carbon dioxide tank without removing liquid carbon dioxide from the tank. The valve allows a user to orient a siphon tube of the valve assembly relative to the inside of a propellant tank. The valve consists of an outer body portion and an inner body portion. The inner body portion is received in the outer body portion. The outer valve body portion contains threads that are used to couple the outer valve body portion with threads of a neck of the tank. The outer valve body includes a hollow passageway that receives the inner body portion and is in communication the pressure relief valve. The inner valve body portion is received into the hollow passageway of the outer valve body such that the inner valve body can rotate with respect to the outer valve body. The inner valve body includes components for introducing the propellant into an associated paintball marker. The inner valve body is associated with a siphon tube that provides fluid communication between the interior of the tank and the inner valve body components. A pressure relief valve may be provided to prevent the tank and/or paint ball gun from over-pressurizing.

REFERENCE TO RELATED APPLICATIONS

This U.S. utility patent application claims the benefit of and/orpriority to U.S. provisional patent application Ser. No. 60/618,042filed Oct. 12, 2004 entitled “Adjustable Anti-Syphon Pin Valve forPaintball Gun”, the entire contents of which is specificallyincorporated herein by reference.

II. TECHNICAL FIELD OF THE INVENTION

The present invention relates to sporting equipment that is used inconnection with paint ball guns and more particularly, to a valveuseable with a paint ball gun to improve the flow of carbon dioxidepropellant from a carbon dioxide storage tank into and through the paintball gun.

III. BACKGROUND OF THE INVENTION

Paint ball is a sport wherein a paint ball gun is used to shootspherical balls that contain paint. Practitioners of the sport use thisgun to shoot their opponents with a paint ball, to simulate war gamesand the like.

A paint ball gun in many respects operates similarly to a normal gun asit fires a projectile. Rather than using gun powder propellant typicallyused in a normal gun to cause a bullet or projectile to fire out of abarrel, a paint ball gun uses compressed gas to fire the paint ball outof the barrel of the paint ball gun. The compressed gas most often usedis compressed carbon dioxide (CO₂). The carbon dioxide is supplied in atank that is removably attached onto the paint ball gun. Examples ofpaint ball guns (often referred to as “markers”) are those manufacturedby Tippmann Pneumatics LLC of Fort Wayne, Ind., whose markers are shownat www.tippmann.com.

Most gun-mountable carbon dioxide tanks are designed to be reusable.When empty, carbon dioxide from a larger storage tank is inserted intothe smaller gun-mountable tank. Within the gun-mounted tank, the carbondioxide will exist both in its liquid and gaseous forms.

In order to propel the paint ball out of the gun, carbon dioxide ispreferably withdrawn from the tank in its gaseous form. Although liquidcarbon dioxide can be withdrawn, it is not desirable to withdraw liquidcarbon dioxide because at least two adverse events are more likely tooccur from the withdrawal of liquid carbon dioxide instead of gaseouscarbon dioxide.

The first potentially adverse event is that propulsion of a paint ballfrom a gun with liquid (as opposed to gaseous) carbon dioxide, resultsin a white cloud of carbon dioxide gas being emitted from the gunbarrel. This emission of a gas cloud has the disadvantage of providing avisual signal to the player's opponent of the position of the shootingplayer, thus making the shooting player more vulnerable to attack fromhis opponents.

The second adverse event occurs because liquid carbon dioxide that iswithdrawn from the tank will tend to expand into gaseous carbon dioxide.During this expansion process, the liquid carbon dioxide works much likea refrigerant, such as Freon®, and chills its surroundings. Thisrefrigerant-like chilling by the liquid carbon dioxide has been known tofreeze up the operating mechanism of paint ball guns, thereby preventingthe paint ball gun from further operation until it thaws.

From the foregoing discussion, it can be appreciated that it isdesirable to position the gun and the carbon dioxide tank in relation toeach other, so that only gaseous carbon dioxide is withdrawn from thetank. With most paint ball guns, the carbon dioxide tank is positionedwith respect to the gun so that the axis of the carbon dioxide tank isoffset by about seven degrees (7°) from the axis of the gun's barrel. Itshould also be noted that the typical manner by which the carbon dioxidetank is affixed to the gun is through a screw-mounted thread that iscontained on the cap on the top of the tank.

The axis of the cap of the tank is disposed co-linearly with the axis ofthe carbon dioxide tank. Threads are formed on a radially outwardlyfacing surface of the cap of the tank. Typically, these male threads arethen threadedly engaged to female threads that are found on or near thestock of the gun, and the tank is rotated about its axis until the tankis fully engaged with the female threads.

When the tank is attached to the gun, and the gun is held in its firingposition, the gaseous carbon dioxide will typically tend to reside atthe top of the tank, whereas the liquid carbon dioxide will tend toreside at the bottom of the tank. The “top” or “bottom” of the tank atwhich the respective gaseous and liquid carbon dioxide will residedepends upon the particular orientation of the tank. If, for example,one could imagine a carbon dioxide tank set up on its base on a table,the gaseous carbon dioxide would typically reside near the cap, or theentrance valve that would then be located near the top. Conversely, ifthe carbon dioxide tank were held upside down so that cap was pointeddownwardly, the gas would then accumulate near the base of the tank,which, in that orientation would be the upward-most point of the tank.

Because of the gaseous carbon dioxide at the top proximity of a carbondioxide tank, the inflow end of the withdrawal tube is usuallypositioned co-linearly with the cap, just under the underside surface ofthe cap. Although this inflow tube positioning results in gaseous carbondioxide being withdrawn from the tank a majority of the time, room forimprovement exists in increasing the percentage of gaseous carbondioxide withdrawals, and decreasing the percentage of liquid carbondioxide withdrawals.

As alluded to above, a straight siphon tube that is disposed co-linearlywith the axis of the tank does not perform that well. A straight tubedoes not perform that well because, depending upon the level of gas inthe tank, a tube that is placed basically in the “middle” of the tank islikely to withdraw liquid carbon dioxide rather a gaseous carbon dioxidein a situation wherein the tank is more than half full. Even if the tankis less than full, movement of liquid within the tank tends to increasethe amount of liquid carbon dioxide that is withdrawn, because theliquid carbon dioxide in an almost-full tank is likely to reside justbelow the entrance to the tube.

It would appear that the percentage of gaseous-to-liquid withdrawalscould be improved by placing the inlet to the withdrawal tube closer toa side surface of the tank, and in particular, that portion of the sidesurface that is positioned above the axis of the tank.

At first blush, an elbow-shaped tube that had its inlet disposedadjacent to a radially inwardly facing surface of the inside of the tankwould be an improvement that would increase gaseous carbon dioxide toliquid carbon dioxide withdrawal percentage. Interestingly, such is notthe case. To understand why, it is helpful to review the structure andorientation of the tank, and the positioning of the withdrawal or“siphon” tube.

When the carbon dioxide tank is affixed onto a gun, one can imagine thatthe tank would have an orientation similar to a clock if one cut a planethat was perpendicular to the axis of the tank. Imagine further thatclock position numbers (e.g. 1, 2, 3 . . . 12) were affixed on to theradially outwardly facing cylindrical surface of the tank. If one fixeda clock-like orientation onto the cylindrical outer circumference of thetank so that one position was arbitrarily labeled as 12:00 o'clock, withother positions around the surface being labeled appropriately (e.g.1:00, 2:00, 3:00 . . . 11:00), one would then have a marked tank thatwould enable you to keep track of its rotational orientation, as thethreads of the tank cap were rotated into engagement with the femalethreaded receiving port on the gun.

Before the tank began being rotated into engagement with the threadedreceiver, the tank would have a starting orientation. For exemplarypurposes, imagine that at this starting (or “disengaged”) orientation,the tank was oriented so that the 12:00 position was pointing “straightup” in the same orientation as “12:00” appears on a clock face.

When the tank is fully rotated on to the receiving port of the gun, itwill assume a “fully engaged” orientation. The position of the 12:00marking on the tank, when it is the fully engaged position will dependupon a variety of factors, such as the number of threads, and startingposition of the tank. Importantly, the “12:00” position that is markedon the tank may now be positioned at some other position, such as 3:00,4:00 and 9:00, etc.

If an elbow-shaped tube, such as the one described above were properlyorientated so that the entrance to the inflow tube was disposed adjacentto the top of the tank when the tank was affixed onto the gun (i.e.12:00 position), the tube would be more efficient in withdrawing gaseousrefrigerant from the tank (when compared to a “straight” tube).Conversely however, if the tube were oriented so that the entrance tothe tube was disposed adjacent one of the lower walls (e.g. the 6:00position), the tube would be situated as to withdraw a significantlygreater percentage of liquid carbon dioxide than a straight tube.

One difficulty with using such an elbow tube is orienting the tube inthe carbon dioxide tank to ensure that the tube will be positionedadjacent to the upper wall of the tank because one is never sure exactlywhere the tube will be positioned after the tank is screwed onto thegun.

Therefore, one object of the present invention is to provide anadjustable tube that enables the user to adjust the siphon tube to aposition wherein the tube is disposed adjacent to the top of the tankafter the tank is affixed onto the gun.

Another object of the present invention is to provide a valve assemblyfor a paintball gun that allows user adjustment of a siphon tube of thevalve assembly to withdraw a greater amount of gaseous carbon dioxidefrom the tank rather than liquid carbon dioxide gas from the tank.

IV. SUMMARY OF THE INVENTION

The present invention is a valve designed for use with a paint ball gunto remove gaseous carbon dioxide from a carbon dioxide tank withoutremoving liquid carbon dioxide from the tank. The valve is particularlydesigned for being inserted into the hollow interior of areduced-diameter neck portion of a gun-mounted carbon dioxide tank.

In one form, the present invention is a valve assembly for a paintballmarker that allows a user to orient a siphon tube of the valve assemblyrelative to the inside of a propellant tank. In another form, thepresent invention is a valve assembly for a paintball marker thatprovides a pressure relief valve.

The valve consists of three major components, an outer body portion, aninner body portion and a pressure relief valve. The inner body portionis received in the outer body portion. The pressure relief valve isreceived by the outer body portion.

The outer valve body portion contains male threads that are used tocouple the outer valve body portion with female threads of a radiallyinward facing surface of the neck of the tank. The outer valve bodyincludes a hollow passageway that receives the inner body portion and isin communication the pressure relief valve.

The inner valve body portion is received into the hollow passageway ofthe outer valve body such that the inner valve body can rotate withrespect to the outer valve body. The inner valve body includes valvingfor introducing the propellant into an associated paintball marker. Theinner valve body is associated with a siphon tube that provides fluidcommunication between the interior of the tank and the inner valve bodyvalving.

A burst or pressure release valve is used to prevent the tank and/orpaint ball gun from over pressurizing. The burst valve contains a valvetherein that is set at a predetermined pressure (usually about 1500psi). If the pressure within the tank, or paintball gun exceeds thispressure, the valve within the burst valve is designed to open, tothereby allow gas to vent through a port to the atmosphere. This willprevent the likelihood of an explosion. In one form, the burst valve isattached to the outer body portion by coupling the male threads of theburst valve to female threads of the outer valve body portion.

A C-shaped retaining ring is provided for axially retaining the innervalve assembly (inner valve body portion) within the interior passagewayof the outer valve assembly (outer valve body portion) while stillmaintaining the ability of the inner valve assembly to rotate relativeto the outer valve assembly. The retaining ring is placed into acircumferential groove of the interior passageway to axially retain theinner valve assembly. The inner valve body portion contains anelbow-shaped siphon tube, that is preferably, but not necessarily madeof copper. The inlet of the siphon tube is preferably, but notnecessarily, angled (formed as an angle with respect to the axis of thesiphon tube). The siphon tube is used to vent carbon dioxide gas frominside the tank to the atmosphere. The siphon is also bent slightly asit extends from the inner valve body portion) and may be of differentlengths.

A turning or adjustment tool is provided to allow the rotationaladjustment, position or orientation of the inner valve body portion withrespect to the outer valve body portion. The adjustment tool is used toadjust, position or orient the siphon tube relative to the interior ofthe tank typically once the valve assembly is connected to the tank.Particularly, once the outer valve body portion is coupled to the tank,the inner valve body portion and thus the orientation of the inlet ofthe siphon tube may be adjusted as appropriate.

The turning tool has a finger engaging gripping surface which has aknurled outer surface. The knurled outer surface improves usergripability. The turning tool allows the user to rotate the siphon tubeto the best position to allow gas to vent through the tube instead ofliquid. In doing so, this increases efficiency of gaseous carbon dioxideremoval from the tank.

In one form, the siphon tube inflow end has an angled cut such that thetube actually engages the inner surface of the tank. When the siphontube is rotated within the tank, an audible “scratching” sound will bemade to signal relative rotational movement and position within thetank.

V. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of an embodiment of an anti-siphon valveassembly according to the principles of the present invention, theanti-siphon valve assembly illustrated with respect to reception onto agun-mountable carbon dioxide tank and with a tool for orienting a siphontube of the valve assembly with respect to the carbon dioxide tank;

FIG. 2 is a side view of the exemplary anti-siphon valve assembly ofFIG. 1 mounted onto the carbon dioxide tank, the anti-siphon valve shownwith the orientation tool coupled thereto for rotating/orienting aportion of the valve before mounting onto a gun;

FIG. 3 is a sectional view of the exemplary anti-siphon valve assemblyof FIG. 1 installed on a carbon dioxide tank, the sectional viewillustrating only a front portion of the carbon dioxide tank;

FIG. 4 is an end view of the exemplary anti-siphon valve assembly ofFIG. 1 taken along line 4-4 of FIG. 2; and

FIG. 5 is a top level flow diagram of a method for releasing gas from apaintball marker tank in accordance with the principles of the presentinvention.

VI. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An exemplary valve or valve assembly 100 according to the principles ofthe present invention is shown in the Figures. The valve 100 is designedfor being inserted into the hollow interior 25 of the reduced-diameterneck portion 27 of a gun-mountable carbon dioxide (CO₂) tank 16 and beadjusted via tool 15.

An exemplary cylindrical gun-mountable carbon dioxide container 16 isdesigned to hold approximately 20 oz. of carbon dioxide, although thetank 16 is typically designed to have sufficient volume to holdsignificantly more than 20 ounces. The tank is designed to be largeenough to hold a sufficient charge of carbon dioxide to enable a user ofthe tank to have sufficient propellant to shoot a large number of paintballs or other projectiles. However, the tank 16 is also designed to besmall enough, so that the tame will not be cumbersome to the user whenthe tank and gun combination are carried around by the paint ball user.It should be appreciated that other types and/or styles of tanks may beused.

The carbon dioxide tank 16 is designed to be refillable. In typical use,when the user goes to a paint ball establishment, his/her carbon dioxidetank is filled with propellant at the establishment. The tank may berefilled numerous times.

It is typical practice for the establishment to place approximately 20oz. of liquid carbon dioxide into the typical tank. When so “filled”,approximately two-thirds of the volume of the interior of the tank willcontain liquid carbon dioxide, with the remaining one-third containinggaseous carbon dioxide. As stated above in the Background of theInvention, the inflow tube for the tank is placed adjacent to the cap ofthe tank so the gaseous carbon dioxide is withdrawn from the tank 16,rather than liquid carbon dioxide.

The user will then screw the cap of the tank 16 onto the stock of thegun (not shown). The receiving female threads (not shown) of the stockof the gun are positioned so that the tank 16 is oriented generallyhorizontally, but having the axis of the tank 16 offset approximatelyseven degrees (7°) from the axis of the barrel of the gun.

Referring specifically to the Figures, the valve 100 includes an outervalve body, outer valve body portion or outer valve assembly 1 that ispreferably, but not necessarily, machined from brass. The outer valvebody 1 includes a generally cylindrical proximal portion 22 having athreaded outer surface 23. Threaded outer surface 23 has male threadsthat are sized and designed to be received by female threads 29 that areformed on the radially inwardly facing surface of the neck 27 of thetank 16 (see e.g. FIG. 3).

The valve body 1 also includes a distally disposed threaded portion 24that includes male threads that are sized and positioned for beingreceived by the female threads of a gas-receiving port of a paint ballgun or marker (not shown). A cap portion 26 of the valve body 1 has arelatively greater diameter than either the proximal threaded portion orthe distal threaded portion 24, and includes a pair of opposing flats 28that can be gripped by a wrench for threadedly engaging the outer valvebody 1 to the internal threads 29 of the neck 27 of the tank 16 and thusthe tank 16 itself. The valve body 1 includes a generally hollowinterior passageway 34 for receiving the inner valve body 2. As will beexplained later, the inner valve body 2, is disposed co-axially with theouter valve body 1; is axially retained with respect to the outer valvebody 1; and is rotatable with respect to the outer valve body 1. Thepassageway 34 is in fluid communication with atmosphere via a bore 32.

The cap portion 26 of the body 1 includes an axially inwardly facingsurface 30 that is disposed adjacent to an O-ring 6. The O-ring 6provides a seal against the end of the neck 27 for preventing gas fromescaping out of the tank 16 and past the outer valve body 1. The surface30 abuts the end of the neck 27 of the tank 16. A distal O-ring 7 issized and configured to fit within a groove 7A at the distal end 31 ofthe outer valve body 1. Distal O-ring 7 is provided for helping to sealvalve body 1 within the gas receiving port (not shown) of the paint ballgun to prevent gas from leaking out of the gas receiving port of thepaint ball gun.

A burst, pressure release or pressure relief valve 9 has a threadedradially outwardly facing surface 38 for threaded engagement with femalethreads 40 within the radially extending fluid passageway 32 of the capportion 26. A hex head 45 is provided on the top of the burst valve 9for allowing engagement with a hex tool (not shown) for inserting andremoving the burst valve 9 into the bore 32 of cap portion 26. The burstvalve 9 also includes a vent or venting port 44 through which gas canpass from the interior of the body 1 and thus the interior of the burstvalve 9 to atmosphere.

The purpose of the burst valve 9 is to prevent the tank or gun fromexploding if an over pressure condition exists within the gun or tank16. The burst valve 9 has a port valve contained therein that is incommunication and/or associated with the vent port 44 and the interiorpassageway 34. The port valve is set for or at a predetermined pressure(usually about 1500 psi) relative to the gun or marker being used and/orthe tank. If the pressure within the tank 16 or the paint ball gunexceeds this pressure, the valve within the burst valve 9 is designed toopen, to thereby allow gas to vent through port 44 to atmosphere. By soallowing the gas to vent, the over pressure situation within the tankwill be relieved, thus reducing the likelihood of an explosion.

The inner valve body 2 is disposed within the hollow passageway 34 ofthe outer valve body 1. The inner valve body 2 is coupled to the outervalve body 1 such that the inner valve body 2 can rotate, swivel, pivotor turn with respect to the outer valve body 1, but which is axiallyrestrained. The inner valve body 2 includes a main body portion 59 thatis generally cylindrical in configuration, and includes a hollowinterior 48. A radially outwardly facing, axially extending cylindricalsurface of the main body portion 59 includes first and second recessedgrooves 5A, 5B that are provided for receiving identical O-rings 5, 5.The O-rings 5, 5 extend between an outer surface of the main body 59 ofthe inner valve body portion 2 and the radially inwardly facing, axiallyextending interior wall of the passageway 34 of the outer body 1. Thisprevents gas from leaking between the outer surface of the inner valvebody 2 and the inner surface 34 of the outer valve body 1.

The main body portion 59 of the valve inner body assembly 2 does notcontain any threads on its radially outwardly facing surface. Femalethreads 49 are formed in the inner surface of the interior 48 to receivethe male threads 36 of the tube bolt 3. Through this arrangement, thetube bolt 3 is coupled to the main body portion 59 so that rotation ofmain body portion 59 rotates tube bolt 3 and tube 17. Thus, rotation ofthe inner body 2 relative to the outer body 1 positions, orients oradjusts the inlet 97 of the siphon tube 17 relative to the main body 1and a position relative to the tank 16.

A C-shaped retaining ring 4 is provided for retaining the inner valveassembly 2 within the interior passageway 34 of the outer valve assembly1. Particularly, the retaining ring 4 axially retains the inner valveassembly 2 relative to the outer valve assembly 1 but permits rotationof the inner valve assembly 2 relative to the outer valve assembly 1.Retaining ring 4 fits into a circumferential groove 52 formed on theinterior of the passageway 34.

A distal portion 65 of pin 14 includes a plunger pin 79 (see e.g.FIG. 1) having a tip 69 (see e.g. FIG. 3), and three blind holes 64 a,64 b, 64 c, formed in end surface 83 of the tip 69 (see e.g. FIG. 4).The holes 64 a, 64 b, 64 c are sized and configured for receiving thethree axially extending prongs 66 (FIG. 1) of the turning tool 15. Thedistal end 69 of the pin 14 comprises the distal end of plunger pin 79and is axially movable within the passageway 48, to allow gas to flowthrough the air passageway 48 when the end 69 is depressed to axiallymove pin 14 in a proximal direction, toward tube bolt 3 and copper tube17.

The distal portion 65 comprises a valve seat 11 that comprises arelatively larger diameter portion of the pin 14. A urethane seal 10 isapplied onto the pin 14 proximally of the valve seat 11. The valve seat11 has two raised portions, with a recessed groove 11 a that is disposedbetween the two relatively larger diameter portions. The groove 11 a isprovided for receiving O-ring 11.

The valve pin 14 does not include an interior passageway through whichgas flows, since gas flows around the outside of the pin 14. At theproximal end of the pin 14 is a hex portion 68 that has an axiallyinwardly facing surface 71 that serves as a seat for the distal end 73of spring 13.

Spring 13 is a compression spring, such that when the device 100 isassembled, the spring 13 is compressed, to thereby exert an axiallyoutwardly biased force (an expansionary force) to separate hex portion68 (and hence pin 14) from tube bolt 3 as far as possible. As theposition of tube bolt 3 is fixed with respect to the main body portion59 of the inner valve assembly 2, the spring 13 exerts a force to pushthe pin 14 axially outwardly, so that the valve seat 65 closes thedistal end of the valve body, to prevent the passage of gastherethrough.

The proximal portion 82 of pin 14 is generally cylindrical inconfiguration, and has a diameter that is slightly smaller than the hexportion 68, but slightly larger than the central portion of the pin 79.The proximal portion 82 includes a distal end 89. The proximal portion82 is received interiorly 73 of/by the spring 13, and thereby retainsthe spring 13 in its appropriate position on the pin 14. The tube bolt 3includes a threaded portion 88 having threads 36. The threads 36 engagethe female threads 49 of the main body portion 59. The hex portion ofthe tube bolt 3 is provided for enabling the user to tighten the tubebolt 3 into engagement with the main body portion 59. An elbow-shapedsiphon tube 17 extends proximally from the tube bolt 3. The siphon tube17 is preferably, but not necessarily, made from copper. The siphon tube17 includes an axially extending portion 91, an elbow-like bend 95, anda radially extending portion 99 that terminates at the inflow port,inlet or the like 97 of the interior passageway of the hollow siphontube 17. Preferably, but not necessarily, the tube 17 and especially theradially extending portion 19 are sized so that the opening 97, whenplaced in the cylindrical carbon dioxide tank 16 will be disposedadjacent to the interior side surface 105 of the cylindrical tank 16(see FIG. 3).

Preferably, inflow end of the tube 17 has an angled cut, so that theproximal most end of the angle cut tube will actually engage surface105, so that as the tube is rotated within the cylindrical tank 16, anaudible “scratching” sound will be made that both signals the movementin the tube 17 in the tank 16, and also helps to indicate the relativerotational position of the tube 17 within the tank 16. The size andshape of the siphon tube 17 will, to a large extent, be determined bythe size and shape of the tank 16. It will be appreciated that differentsizes and possibly different shaped siphon tubes 17 would be used inconnection with cylindrical tank 16 that are shaped differently than theone shown in the drawings.

The tube 17 is preferably press fit or crimped into tube bolt 3, or, maybe welded or soldered. When the device 100 is assembled, as shown inFIG. 3, the inner valve body 2, tube 17 and pin 14 are fixedlypositioned with respect to each other but rotatably movable with respectto the outer valve body 1.

When so assembled, it is preferred that the threads 36 of the tube boltbe configured so that one of the blind holes, such as 64 a (relative tocentral pin 14) lines up with the radial direction in which the tube 17extends. Viewed another way, when the device 100 is assembled, the openend 97 of the tube 17 should be positioned to open up and extend in thesame direction, as blind hole 64 a.

The inner tube and inner valve body assembly 2 is then placed with theinterior passageway of the outer valve body 1, and the outer valve body1 is coupled to the cylindrical tank 16. When so assembled, one can thenview the relative position of blind hole 64 a, and by so doing, will beable to readily deduce the position of the opened-end 97 of the tube 17,as the two should be placed in the same direction. More importantly fromthe user's standpoint, as the blind hole 64 a is visible from theexterior of the tank when the valve assembly 100 is inserted therein,the alignment of the blind hole 64 a with the direction of extent of theradial portion 99 of the inner tube 17, will enable the user toeffectively “view inside” the cylindrical gas tank 16, so that the userwill know where the inflow end 97 of the tube is pointed.

The inner valve body turning tool or configuration 15 is generallycylindrical in configuration and includes a knurled outer surface 113 toimprove a user's grip (i.e. “gripability”). Three prongs, each of whichis labeled 66, are disposed at 12:00, 3:00 and 9:00 to the axis of thetool 15 and extend axially outwardly from a surface 91 of extension 67along lines that are parallel to the axis of the inner valve body 2 andthe tool 15. As is described in more detail below, the prongs 66 areengagable within three similarly positioned blind holes 64 a, 64 b and64 c that are formed in the axially outwardly facing, radially extendingdistal surface of the inner valve body 2 (see e.g. FIG. 4). Rotation ofthe tool 15 thus rotates the inner valve assembly 1 (siphon tube 17)relative to the outer valve body 2. The siphon tube 17 and thus theinlet 97 are positionable relative to the tank 16 and more particularlyto a known orientation relative to the interior of the tank.

To adjust the valve, the user affixes the valve-containing cylindricaltank 16 onto a gun, and rotates the tank 16 until it is fully engaged onthe gun. The user then places a mark, with a marker or marking tool,such as mark 109, at the top dead-center position of the exteriorsurface 111 of the tank 16 (see FIG. 2). The user then removes thecylindrical tank 16 from the gun. The user then employs the valveadjusting tool 15, by inserting the axially extending legs 66 into thethree blind holes 64 a, 64 b and 64 c. The adjusting tool 15 can includea mark, that may comprise a recessed divot, raised “pimple” or the like123 that indicates the position of the axially protruding leg 66 that ispositioned to engage the blind hole 64 a that is lined up with theposition of the inflow tube 17, and more particularly, with the inflowopening 97 of tube 17. The knurled surface 113 of the adjusting tool 15can then be gripped by the user, and the tool 15 rotated until such timeas the top dead center mark 123 of the adjusting tool 15 lines up withthe top dead center hash mark 109 (FIG. 2) of the cylindrical tank 16.When so positioned, the user will know that the inflow opening 97 of thetube 17 is pointing up, and will point up when the cylindrical tank 16is threadedly engaged onto the stock of the paint ball gun.

The above valve adjustment procedure may be summarized in the flow chartor diagram 200 of FIG. 5. Initially, in step 202, the valve 100 iscoupled to the tank 16. In step 204, a mark 109 is made on the exterior111 of the tank 16 at a top dead center (TDC) position of the tank asmounted onto and thus relative to the gun. Thereafter, in step 206, thetank 16 is removed from the gun.

In step 208, the tool 15 is engaged with the inner valve body 2 of thevalve 100. Particularly, the prongs 66 are properly aligned with andinserted into the bores 64 a, 64 b, 64 c of the inner valve body 2. Thetool 15 is then rotated in step 210 until a TDC (hash) mark on the tool15 aligns with the TDC mark 109 on the tank 16. The tool is thenremoved. In step 212, the tank is then placed back onto the gun.

One additional feature of this adjustability is that it enables a tank16 to be readily transferred between guns. For example, it is likelythat the valve 100 will only need to be adjusted once in order to enablea particular tank to fit onto a particular gun. However, different gunshave different thread arrangements. As such, if the same tank is used ona second gun, the tube opening 97 may not point to top dead centerwithin the tank 16. However, by following the procedure outlined above,the user can quickly adjust the tank 16 to fit this second gun. As willbe appreciated, this feature would be especially handy in situationswherein the paint ball facility operated a tank exchange program,wherein users could trade in their empty tanks for a full tank at thefacility, rather than have their existing tanks filled at the facility.

In summary, the present invention provides a vehicle for increasing theefficiency of gaseous carbon dioxide (CO₂) removal from a tank 16 thatis attached to a paint gun, and also makes tanks more universallyadaptable to a wide variety of different guns, having different threadattachment configurations.

Although the invention has been described with reference to thepreferred embodiments thereof, it is to be understood that all changesand modifications and devices that come within the spirit of theinvention and the appended claims are desired to be protected.

1. A valve for use with a paint ball marker having a hand hold mount anda gas port for receiving propellant from a tank, the valve comprising:an outer valve body portion having a first coupling for coupling theouter valve body to a tank and a first fluid passageway; an inner valvebody portion disposed in the first fluid passageway of the outer valvebody portion and having a first body portion fluid passageway fordirecting fluid through the inner valve body portion; and a burst valvemember connected to the outer valve body portion and in fluidcommunication with the first fluid passageway to prevent the tank andpaint ball marker from over pressurization.
 2. The valve of claim 1,wherein the outer valve body portion and inner valve body are coupled asto allow the inner valve body portion to rotatably move within the firstfluid passageway of the outer valve body portion.
 3. The valve of claim1, wherein the burst valve member includes a port to allow gas to ventto atmosphere during an over pressurization of the tank or paint ballmaker.
 4. The valve of claim 1, wherein the outer valve body portion iscoupled with the inner valve body by use of a C-shaped retaining ring.5. The valve of claim 1, wherein the inner valve body portion includes ahollow tubular member radially extending from the inner valve bodyportion.
 6. The valve of claim 5, wherein the hollow tubular member hasan elbow-like bend.
 7. The valve of claim 5, wherein the hollow tubularmember extends radially into the tank wherein the tube is disposedadjacent to the top of the tank after the tank is affixed onto the gun.8. The valve of claim 5, wherein the hollow tubular member is positionedat a vaporous end the tank so that only gaseous carbon dioxide iswithdrawn from the tank thereby increasing the efficiency of gaseouscarbon dioxide removal from the tank.
 9. The valve of claim 5, whereinthe hollow tubular member includes an angled cut so that the cut tubeengages with the inner surface of the tank creating an audible sound tosignal movement of the hollow tubular member within the tank and also toindicate relative rotational position of the hollow tubular member. 10.A valve assembly coupleable between a tank for holding a gas propellantand a paintball marker, the valve assembly comprising: an outer valveassembly having a first threaded end for threadedly engaging the tank, asecond threaded end for threadedly engaging a gas input port of thepaintball marker, and a first fluid passageway disposed through thefirst and second threaded ends; an inner valve assembly having aproximal end, a distal end, and a second fluid passageway disposedthrough the proximal and distal ends, the inner valve assembly disposedin the first fluid passageway so as to be axially restrained butrotatable relative to the outer valve assembly; and a siphon tubecoupled with and extending from the inner valve assembly, the siphontube in fluid communication with the second passageway and having aninlet rotatable with the inner valve assembly.
 11. The valve assembly ofclaim 10, further comprising: a coupling member disposed in the firstfluid passageway and configured to restrain axial movement of the innerbody relative to the outer body while allowing rotation of the innerbody relative to the outer body.
 12. The valve assembly of claim 11,wherein the coupling member comprises a C-shaped retaining ring.
 13. Thevalve assembly of claim 10, wherein the inner valve assembly includesconfigured bores on an axial end surface of the distal end of the innervalve assembly, the configured bores adapted to receive configuredprongs of a tool for rotating the inner valve assembly relative to theouter valve assembly.
 14. The valve assembly of claim 10, furthercomprising: a pressure release member connected to the outer valve bodyportion and in fluid communication with the first fluid passageway toprevent the tank and paint ball marker from over pressurization.
 15. Thevalve assembly of claim 14, wherein the pressure release member includesa port to allow gas to vent to atmosphere during an over pressurizationof the tank or paint ball maker.
 16. The valve of claim 10, wherein theinlet is angled for engaging the inner surface of the tank to create anaudible sound to signal movement of the siphon tube within the tank andalso to indicate relative rotational position of the siphon tube.
 17. Amethod for extracting gaseous carbon dioxide from a tank of gaseous andliquid carbon dioxide, the method comprising: a. coupling a valveassembly to a carbon dioxide tank, the valve assembly having a siphontube that is rotatably positionable relative to the carbon dioxide tank;b. placing a mark on an exterior of the tank, the mark corresponding toa top dead center position of the tank relative to a gun; c. removingthe tank from the gun; d. engaging a portion of the valve assemblyassociated with the rotatable siphon tube with an adjustment tool, theadjustment tool having an alignment mark which corresponds to a top deadcenter position of the siphon tube inlet relative to the tank when thealignment mark is coaxial with the exterior tank mark; e. rotating theadjustment tool until the tool alignment mark coaxially aligns with theexterior tank mark; and f. re-coupling the tank to the carbon dioxidetank.
 18. The method of claim 20, wherein the valve assembly comprises:an outer valve assembly having a first threaded end for threadedlyengaging the tank, a second threaded end for threadedly engaging a gasinput port of the gun, and a first fluid passageway disposed through thefirst and second threaded ends; an inner valve assembly having aproximal end, a distal end, and a second fluid passageway disposedthrough the proximal and distal ends, the inner valve assembly disposedin the first fluid passageway so as to be axially restrained butrotatable relative to the outer valve assembly; and a siphon tubecoupled with and extending from the inner valve assembly, the siphontube in fluid communication with the second passageway and having aninlet rotatable with the inner valve assembly.
 19. The method of claim17, wherein the valve assembly comprises: an outer valve body portionhaving a first coupling for coupling the outer valve body to a tank anda first fluid passageway; an inner valve body portion disposed in thefirst fluid passageway of the outer valve body portion and having afirst body portion fluid passageway for directing fluid through theinner valve body portion; and a burst valve member connected to theouter valve body portion and in fluid communication with the first fluidpassageway to prevent the tank and the gun from over pressurization.